I have used it in the past, it has useful options being both a sort of group forum as well as a group verbal chat program.

Unfortunately the complexity makes it just a little too much for me.

Skype is another option for small groups and works well enough.

The modern apps and interface is really clean - I think if that is an issue in the past - Big changes now. I keep seeing it popup as the thing to use for your voice chat now for games and increasingly instead of skype, snapchat etc.With the Skype redesign, lots of people are turning to Discord and in terms of business - Slack.